The "Dirty Harry"
Principle

by Paul H. DavisReprinted with
permission of FAA Aviation News

There's a
line from an old "Dirty Harry" movie - I'm sure you know the one I'm
talking about - where Clint Eastwood, as Inspector Harry Callahan,
makes the now famous assertion that "a man has got to know his
limitations." Well, nowhere is that concept truer than in general
aviation.

The secret
to avoiding an aircraft accident is knowing what and where those
"limitations" are and knowing how not to exceed them. For every flight
there is a LINE that when crossed may result in an aircraft mishap. I
say "may" because sometimes we cross that line and then retreat behind
it in time to avoid the mishap, or maybe we're just fortunate enough
to wind up wandering back behind the line; but the potential for a
mishap is still there.

There are
three major elements for each flight: the pilot, the aircraft, and the
environment. The first two of these are subject to limitations. The
third usually imposes limitations on the other two. Every year
hundreds of aircraft accidents occur simply because the pilot chose
to, or inadvertently exceeded, these limitations. What might cause a
pilot to do this? Let's look at a few reasons.

First off,
many pilots either don't know, or have forgotten, the limitations of
their aircraft and also may ignore pilot limitations for themselves.
The regulations require that aircraft operating limitations be carried
on board the aircraft, but how many general aviation (non-part 121 or
135) pilots regularly take time to refresh themselves with this
information? Do you know all the applicable speeds for the aircraft
that you fly? When was the last time you went out and practiced doing
various types of stalls? How about the maneuvering speed for your
aircraft or the weight and balance limitations? Do you remember how
much usable fuel your aircraft is capable of carrying or what the
ACTUAL fuel burn rate of the aircraft engine is? When was the last
time you went out and practiced ground reference maneuvers or short
and soft-field takeoffs and landings with a CFI (if you're rusty, of
course) except maybe during a flight review? Now are you starting to
get the picture? Many pilots just don't do much training until it
becomes mandatory, but why?

One of the
reasons I have found for pilots avoiding regular training is that some
feel like they just don't need it to be safe pilots. Others are quite
content to simply fly from point A to point B and may actually be
uncomfortable performing training maneuvers. The bad thing about this
is that the less training maneuvers are practiced, the more
uncomfortable they may become because of lack of proficiency. Many
pilots who get to this point, and I never have been able to figure
this one out, are very reluctant to contact a flight instructor for
some good refresher training.

Then, there
is the weather. This is an area of flying where it is very easy to
exceed limitations. If you don't believe it, check out the National
Transportation Safety Board (NTSB) aircraft accident report pages.
They're chock full of mishaps that occurred because the pilot either
didn't know or chose to exceed environmental limitations. Continued
VFR into IFR conditions remains one of the leading causes of general
aviation accidents. What causes pilots to exceed weather limitations?
Well, sometimes it's the need to be at a certain place at a certain
time, or maybe the pilot feels pressure to make the trip anyway
because of the desire to not look bad in front of passengers. You can
be assured that whatever the reason, in retrospect, it's not worth
dying for, yet these types of accidents continue to occur all too
frequently. There are plenty of other reasons that pilots exceed
limitations. Remember those five hazardous attitudes: Macho,
Anti-authority, Invulnerable, Resigned, and Impulsive. You can be sure
that these have a pretty big influence on pilot decision-making and
have been responsible for more than a few mishaps.

So what can
we do to stack the deck in our favor? The best place to start is with
a "Personal Minimums Checklist" (PMC). As far as I'm concerned it's
one of the best concepts the FAA ever came up with. The Personal
Minimums Checklist helps pilots to assess their piloting skills and
piloting resources to determine if they are properly trained and
equipped to make any flight under given conditions.

The pilot
should also set up a personal training program or agenda with the aid
of a local CFI/Safety Counselor. Most CFI's and pilot examiners that I
know are available for any questions or training concerns a pilot may
have. They would be more than happy to sit down and help set up a
personal training agenda. Most airlines mandate training programs for
their pilots at least semi-annually. What makes us (general aviation)
think we need regular training any less than they do? If you have an
opportunity to attend Cockpit Resource Management (CRM) training and
hazard awareness training, then by all means do so. If there are no
such programs available to you, call your local FSDO Safety Program
Manager or Aviation Safety Counselor and set up a program. They will
be more than willing to accommodate the pilots at your airport.

Analyze
yourself, the airplane, and the environment, thoroughly. Find out
where that limitations line is and then make sure you are operating
comfortably behind it at all times. I've been criticized more than one
time for repeatedly "what ifing" a situation, but that's all right,
because "what ifing" has ultimately saved me more than a little bit of
grief quite a few times, and I'm sure even saved my life somewhere
along the way.

One other
thing I need to mention. Over the years I've learned that we sometimes
exceed our limitations because we don't want to disappoint our
passengers. We all know what happens when we meet our friends or loved
ones at the airport on a beautiful spring day for an enjoyable
sightseeing flight only to find: a puddle of oil under the airplane, a
dead battery, or broken starter. The urge to replenish the oil,
jumpstart, or handprop the airplane is overwhelming. Don't do it! Call
the owner or local mechanic and have the airplane fixed properly. Your
PMC should have stopped you right away, along with Federal Aviation
Regulation Part 91.7 (Civil Aircraft Airworthiness).

What about
the unforecasted weather that moves in when the original forecast
called for "clear and a million?" I have found the best ways to deal
with this situation is to sit down well before the flight and
incorporate my forecast weather limits into the Personal Minimums
Checklist. In other words, I draw my limitations line and then with
feet firmly planted on the ground (usually the day before the flight)
I inform my passengers as to conditions I will and will not accept as
being satisfactory for the flight. A good example of this is the fact
that I set wind gust limitations for each airplane that I fly. I might
set a higher wind gust limit for a larger aircraft that I know will
accept the higher gust factor more comfortably, especially when I am
flying near mountainous terrain. I also review mountain flying
techniques for that area and am well familiar with all the local
terrain features and hazards well before I make the flight. I have
found that passengers respond to this method very well and are much
less disappointed and more understanding when they know ahead of time
that you are adhering to your PMC and have their safety and well-being
at heart. It also lends credibility to your being a safe pilot for
those who have the opportunity to fly with you.

The FAA has
a form for the PMC that you can download right off the Internet or
check with your local FSDO and the Safety Program Manager will be
happy to share copies with you. While you're at it, be sure to attend
local FAA sponsored safety meetings and "WINGS" seminars at your
airport. If your airport is not having any, call the FSDO Safety
Program Manager and ask to be included on their Aviation Safety
Meeting Schedule.

Remember,
the more you practice good risk assessment with your PMC, the better
you will become at learning all your limitations. You will become more
confident and better at making good decisions and that friends and
fellow pilots will make the skies safer for everybody.

Happy
Flying....

Paul H. Davis is with
the U.S. Coast Guard, but is an FAA Aviation Safety Counselor in
Alaska. He is a commercial pilot with Instrument, Multi-engine,
Single-engine, and CFI ratings.